Cloud computing is a popular technology of future mobile communications system, which integrates signal processing units of base stations, and controls each cellular antenna to perform transmission of a downlink signal and receiving of an uplink signal through a radio frequency zoom-out method. By performing integrated signal processing, the cloud computing is capable of performing cross-cell joint signal processing to improve the utilization rate of frequency spectrum, thereby flexibly allocating computing resources. The implementation of the cloud computing will impose huge impact on the network structure of the mobile communications system.
The system structure of the conventional mobile cellular network is illustrated in detail in a specification 3GPP TS 23.002 named “Technical Specification Group Services and System Aspects; Network architecture” and proposed by the Third Generation Partnership Project (3GPP). The system structure of the conventional mobile cellular network has the following features:
(1) Uplink/downlink network data is converged/diverged stepwise. By taking the uplink network data as an example, data generated by each base station of an access network is first converged to a radio network controller (RNC) of the access network, the data of each RNC is converged to a serving GPRS support node (SGSN) of a core network, and the data of each SGSN is converged to a gateway GPRS support node (GGSN), so as to enter an external packet data network (for example, Internet).
(2) Each user has a uniquely determined access network management node in the access network. For example, in an E-UTRAN, the uplink/downlink data of each user is managed by a uniquely determined eNodeB. The core network definitely learns the access network management node of each user, and therefore, it only needs to transmit the network data to the unique access network management node of the user.
(3) All air interface data processing is completed on the access network. The core network is mainly responsible for data convergence and mobility management, and is not involved in the air interface data processing.
When the network data traffic of the access network node is small and the system has a few demands on cross-cell joint data processing, the foregoing system structure is applicable. However, for a mobile cellular system based on cloud computing, the foregoing system structure is not applicable.
According to the classification of the conventional system structure of the mobile cellular network, each cloud computing node should be a node in the access network. Due to the feature of integrated computing, the cloud computing nodes will generate or converge a large amount of network data, and as a result, it is no longer suitable to perform uplink convergence or downlink divergence for the data of the cloud computing nodes in the core network. Therefore, the core network structure of the conventional mobile communications system for stepwise convergence/divergence is no longer applicable due to low efficiency.
Consequently, a new system structure of mobile cellular network capable of adapting the cloud computing technology is required.